Automatic document feeders (ADFs) are used to sequentially feed or move documents from a stack of documents to another location (e.g., to a platen or other type of imaging or non-imaging surface/location). However, ADFs can sometimes inadvertently feed multiple sheets simultaneously. Some ADFs, or devices associated with an ADF (e.g., copiers, scanners, etc.), are equipped with systems to detect simultaneously feeding of multiple sheets. However, such detection systems require expensive sensors, amplifiers, digital logic circuitry and other components that increase the cost and complexity of the ADF and/or ADF-associated device.